I want to start by saying i dont know much about cars but i was recently given a 1999 dodge neon r/t dohc 122k miles. I have no background of the car and when i got the car it did not even run it had been sitting for about 2 years.

I will try my best to explain everything i know currently about the car. I towed the car home and had to hook up a new battery to it but the car would'nt start so we "sprayed" it? and the car started up fine and starts fine every time now. We then checked the plugs for wetness and the oil because i was told it could be the head gasket but everything checked out fine. We then ran a test on it with i believe some blue fluid and it went over the raditor cap? It then turned green indicating a head gasket leak? I was told to buy some Barrs Leak and try to seal it with that to save myself 800$ or so on a mechanic. I went and bought the Barrs Leak and followed the instructions i then found out when i turned the heater on high it blew cool air I have no idea what all this means but the car is still overheating so i guess the barrs leak didnt work. I have no idea what to do and i appolagize for not knowing much about cars but if anyone can lend some advice id much appreciate it.

 

I am not familiar with the color change fluid test but assume is somehow detecting oil in the antifreeze. If in fact the head gasket is blown or the head cracked the only real fix is to replace the gasket and have the head checked for cracks. Barrs does make a product claming to fix these problems http://www.barsproducts.com/1100.htm but, in my experience any of these types of repairs are at best temporary.
The over heating could also be caused by a bad thermostat, cooling fan problems, water pump or air in the cooling system. The lack of heat from the heater could be a problem with the heater controls, bad heater core, air in the cooling system or water pump.

My suggestion would be to have the cooling system pressure tested, if it tests ok then a complete cooling flush and possible a new thermostat.

 

One other thing you can do (and is super cheap - if not free), you can do a compression check to see if there are any problems there. If you don't have a long hosed Compression checker on hand, you can get one on loan from Autozone, Advance, or O'Reillys (pay a deposit and get it back when you return it).

All four cylinders should be within 25% of each other in readings (according to the Haynes manual). Which means if you have readings of about 180psi in a cylinder, no other cylinder should be below 135 (25% of 180 is 45). The service limit is 100psi. A good reading for all 4 cylinders should be about 175 to 195psi.